Reaction products of polymerized polyene higher fatty acids and poly-1, 2-alkylenamides



United States Patent REACTION PRODUCTS 0F POLYMERIZED POLY- ENE HIGHERFATTY ACiDS AND POLY-1,2- ALKYLENAMIDES Paul Fram, Lincoln Township,Washington County, and

George H. Smith, Maplewood, Minn, assignors to Minnesota Mining andManufacturing Company, St. Paul, Minn, a corporation of Delaware NoDrawing. Continuation of application Ser. No. 856,650, Dec. 2, 1959.This application May 13, 1963, Ser. No. 280,081

25 Claims. (Cl. 260-404.5)

This invention relates to polymeric compositions and more particularlyto polymers of higher fatty acids copolymerized with certainpolyfunctional amide-containing monomers.

This application is a continuation of our prior copending applicationSer. No. 856,650, filed Dec. 2, 1959, now abandoned which is acontinuation-in-part of our earlier filed application Ser. No. 683,682,filed Sept. 13, 1957, now abandoned.

It is an object of the present invention to provide thermosettingcurable resin mixtures, including inter alia liquid, solvent-freecompositions which cure smoothly and at relatively low temperatures(often at room temperature) and which when cured produce dense, tough,resinous or elastomenic solids which have good resistance to hightemperature and high humidity and useful electrical insulationproperties. Another object of the invention is to provide moldingcompositions which are resistant to moderately high temperatures. Afurther object of the invention is to provide compositions forencapsulating or embedding electrical circuits and other components. Astill further object of the invention is to provide easily handled,solvent containing compositions which form useful protective coatingswhen applied to surfaces. Other objects of the invention will beapparent from the disclosure hereinafter made.

In accordance with the above and other objects of the invention it hasbeen found that when certain low molecular weight polymers of higherfatty acids are copolymerided with the hereinafter definedpolyf-unctional alkyleneimine derivatives, resinous products areproduced which have highly advantageous properties. They have excellentsolvent resistance as Well as resistance to Water and high humidity and,in addition, have useful electrical insulating properties. They can bemixed and compounded in simple, open mixing equipment rather than closedcontainers and ball mills and when so mixed, they have useful pot livesat ambient temperature, so that they can be used conveniently inassembly line processing. They may be cast in inexpensive open molds,rather than high pressure and/or high temperature molds. They require nosolvents and can be prepared as liquid mixtures containing 100 percentsolidsforming components although they may also be diluted with solventsas desired. In liquid form they penetrate well, e.g., between thewindings of coils and into other inaccessible areas in circuits as wellinto the detail of mold patterns to eliminate trapped air bubbles andprovide complete impregnation or faithful pattern reproduction. Theycure with substantially no volume change to yield solids which closelyconform to the mold or container. In use for molding, encapsulation orpotting, no stresses or strains are introduced into the pattern orcomponent being molded or encapsulated or into the resin itself. Thisproperty is highly advantageous, for example, in the encapsulation ofcomponents which are sensitive to pressure, such as hysteresis loopelements for computers as Well as for the preparation of molds whichwill faithfully reproduce patterns. The curing takes place atsurprisingly low temperatures in 3,318,930 Patented May 9, 1967 view ofthe pot life, often at room temperature. The compositions cure with arelatively low exotherm and hence large encapsulation-s-may be made whendesired without fear of undue build-up of heat during curing. They areparticularly useful in the encapsulation of parts which are so fragileor are of such materials that they are destroyed by heat, and inapplications in which it is difiicult or undesirable to heat the resinand parts to be coated until sufficiently intimate contact between resinand parts is obtained, such as elements and subassemblies for electronicinstruments, for example, computers and the like. They are unreactivetoward and adhere well to copper, glass, reinforced epoxy laminates andother materials commonly used in fabricated electrical circuits.

The compositions of the present invention are extremely stable to heatwhen cured, retaining desirable mechanical and chemical properties athigh temperatures, and are useful as flexible molding materials whichare so resistant to heat that they may be used to prepare molds for therepeated casting of relatively low melting metals.

The compositions of the invention offer unique advantages, e.g., in thefields of flexible molding materials and encapsulation, when compared tothe various other known polymer systems which form low temperaturecuring, solvent-free liquid compositions. Thus, for example, thepolysulfide rubbers are relatively unstable with respect to theirmechanical properties, particularly at elevated temperatures.Furthermore the polysulfide rubbers tend to attack and corrode metals.This is particularly disadvantageous where an electric circuit which isto be encapsulated contains very fine metal wires. Systems cured withisocyanates (e.g. hydroxyl-terminated polyesters cured withdiisocyanates) are sensitive to moisture during preparation and inaddition, some of the isocyanate chemicals, especially those ofrelatively low molecular weights, may have very irritating physiologicaleffects. During curing, the formation of gas and consequent sponging ofthe composition particularly along the surfaces of the encapsulatedcomponent is common, and is obviously disadvantageous. The resultingrubbers soften severely at elevated temperatures and have very pooradhesion to the metal when cured. Ordinary epoxy resin systems generallyrequire at least a short cure at elevated temperatures (of the order of100 C.) to obtain optimum results, or have high exotherm and short potlife after addition of the curing agent, and the resulting resins havepoor impact strength and are generally rather stiff and frangible unlessmodified. The copolymers of the present invention have been found tohave none of these disadvantages.

Low polymers of the higher fatty carboxylic acids which are suitable foruse in the present invention can be characterized as polymeric fattyacids of the drying and semi-drying oils. They are derived fromunsaturated monomers having at least two double bonds and containingcarboxyl groups; and can therefore be designated as polymerized polyenehigher fatty acids. Illustrative monomeric fatty acids of the type usedfor the purpose are octadeoadienoic acids containing two double bonds,like linoleic acid, and octadecatrienoic acids containing three double:bonds such as linolenic and eleostearic acids. The preparation of suchpolymeric polyene higher fatty acids is described, for example, in US.Patents 2,482,761, 2,373,015 and 2,435,478 and in an article in thePaint, Oil and Chemical Review of January 4, 1951 (starting at page 13).They can be prepared by heating the monomeric unsaturated acids in thepresence of water (steam), which is held in the reaction zone bycarrying out the reaction in a pressure vessel. While the actualstructure of the polymeric products is not known with particularity, itappears that the polymerization of the unsaturated fatty acids takesplace by intermolecular condensation at be double bonds. The reactionproducts obtained generally comprise dimers and trimers formed bycondensation of two or three molecules of the higher fatty acids,respectively. Further polymerization can also give rise to tetramers orhigher polymers. Commonly it is observed that a preponderance of thedimeric polymer is formed, in admixture with the trimeric polymer. Whilethe dimeric products can be employed in substantially pure form in thecompositions of the invention, the cured end-products formed fromcompositions containing the trimeric products or the mixture of dimericand trimeric higher fatty acids are especially useful in that theyproduce more durable cured resins. Therefore, it is preferred to usetrimeric or mixtures of dimeric and trimeric or higher polymers of thepolyene higher fatty acids in the compositions of the invention.

The polymerized polyene higher fatty acids which result from thepreparatory processes described in the patents and article referred tohereinabove can be characterized :by their average molecular Weights.Thus, the dimeric, dibasic higher fatty acid polymers prepared from C-18acids have been described as having an average molecular weight of about560 while the corresponding trimeric, tribasic acids have an averagemolecular weight of about 840. Obviously, mixtures of the dimeric andtrimeric acids will have molecular weights which are intermediate thesenumbers, while the tetramers and mixtures containing them will havecorrespondingly higher molecular weights. The reactivity of thepolymerized polyene fatty acids toward the polyfunctio-nal alkyleniminederivatives may be characterized by their acid numbers (the number ofmilligrams of potassium hydroxide required to neutralize 1 gram ofsample). The preferred acid number range for these materials in thepresent invention is from about 50 to about 250. Polymerized polyenefatty acids having acid numbers below this range react with unnecessaryslowness and are difficult to cure completely at lower temperatureswhile those having acid numbers substantially above 250 react so rapidlyas to be difficult to handle under certain conditions, particularly inlarge encapsulations (e.g. excessive exotherms, premature gelling,etc.). The commercially available po lymerized polyene fatty acids,generally have acid numbers from about 170 to about 210 and this forms aparticularly preferred range in the present invention.

Illustrative of the polymerized higher fatty acids which may be employedherein are, for example, a dibasic dimerized linoleic acid product ofapproximately 600 molecular weight which typically has a dimerztrimeracid ratio of about 95:5 percent, an acid number of 188-193, asaponification value of 194-198, a neutralization equivalent of 292-298and a viscosity at 25 C. of approximately 5,600 centistokes (available,under the trade designation Emery 3079-8 polymerized fatty acid); atribasic trimerized linoleic acid product of an average molecular weightof approximately 845 which varies in trimer acid content from about 70to 85 percent (the remainder being composed essentially of dimer acid)and which typically has an acid number of 183-188, a saponificationvalue of 192-198, a neutralization equivalent of 299-306 and a pourpoint of about 13 C. (available under the trade designation Emery 3055-Spolymerized fatty acid); a tribasic trimerized higher fatty acid productof approximately 900 molecular weight which typically has a trimer acidcontent of 90-95 percent (the balance being composed essentially ofdibasic acid), an acid number of 183-188, a saponification value of192-198, a neutralization equivalent of 299-306 and a pour point ofabout 13 C. (available under the trade designation Emery 3162-polymerized fatty acid); a liquid tribasic trimerized higher fatty acidproduct which has a relatively low iodine value, a neutralizationequivalent of about 311 and a calculated acid number of 180 (availableunder the trade designation Emery 3130-R polymerized fatty acid); ahighly viscous liquid black low polymeric product of a higher fatty acidwhich has a neutralization equivalent of 267 and a calculated acid.number of 210 (available under the trade designation. Emery 3215-Rpolymerized fatty acid); a viscous,v liquid, purified, dimerized higherfatty acid product which: has a relatively low iodine value, aneutralization equivalent of about 309 and a calculated acid number of182'- (available under the trade designation Emery 3244-R"' polymerizedfatty acid); a highly viscous light yellow colored liquid tetramerichigher fatty acid product which: has an acid number of about 170 and anaverage molecular weight of about 700 (obtainable under the tradedesig-- nation 4308-1 polymerized fatty acid); etc.

While the structures of these polymerized acids are not. definitelyknown it has been postulated that the structures of the dimer and trimerof linoleic acid are as follows:

Regardless of the accuracy of these proposed structures and of themechanism of polymerization of linoleic acid and other fatty acids,useful products are formed by the reaction of these polymerized polyenehigher fatty acids with the polyfunctional amide-containing monomers asherein described.

Other higher fatty acids from which low polymers suitable for use in thepresent invention may be prepared include those acids present in themixtures of fatty acids derived from soybean oil, peanut oil, linseedoil, dehydrated castor oil, corn oil, tung oil, cottonseed oil, sardineo-il, tall oil and other oils of the drying or semi-drying type. Theprimary constituents of these and other oils of this type are C to Cunsaturated fatty acids together with lesser amounts of saturated acidsof the same chain lengths. The total range of chain lengths of the fattyacid constituents of such oils is from about C to C These polymerizedpolyene higher fatty acids are additionally characterized by beingsubstantially liquid, that is liquid or semi-solid at ordinarytemperatures, or easily liquefied by moderate warming. Furthermore, itis of course possible to use together mixtures of polymerized polyenehigher fatty acids as well as individual polymers in admixture withsmall amounts of unpolymerized saturated or unsaturated higher fattyacids in carrying out the process of the present invention. In fact,less pure commercially available polymerized polyene higher fatty acidproducts commonly are found to contain an amount of unpolymerizedmaterial and these are quite suitable for use in the compositions hereindescribed.

If desired, the polymerized polyene higher fatty acids can be subjectedto hydrogenation to remove residual unsaturation in whole or part.Resinous compositions prepared by employing with these thepolyfunctional alkylenimine derivatives of the invention exhibitenhanced electrical and mechanical properties, especially at higheroperating temperatures.

As noted, the compositions formed using polymerized polyene higher fattyacids and the polyfunctional alkylenimine derivatives as co-monomers areordinarily initially liquid, or semi-solid, substantially percentsolids-forming mixtures. Such compositions are highly advantageousbecause they exhibit little or no shrinkage upon final curing.Furthermore, the liquid nature of these comonomer mixtures is importantin compounding and molding, i.e., simple mixing equipment may in mostinstances be used in place of ball mills and simple open molds "may beused in place of high pressure and/ or high this solution with thepolymerized polyene higher fatty acid. The solvent can then be removed,as by evaporation. Additionally, no gasses are given off by thesolvent-free systems during curing, whereby bubble-free resins arereadily obtained. Because of the relatively low temperature required forcuring, encapsulation or mold preparation may be accomplished where itis difiicult or impossible to heat the wire or circuit to beencapsulated or the mold pattern, e.g., at ambient temperature and atthe location of the circuit component to be encapsulated. When cured,the compositions of the invention retain useful mechanical properties atrelatively high temperatures.

The preferred class of polyfunctional alkylenimine derivatives which areemployed in preparing the polymers of the invention arepoly-1,2-alkylenamides represented by the following illustrativeformula:

wherein R represents a member of the group consisting of divalentaliphatic, e.g., alkylene, radicals having from about 4 to 53 carbonatoms, the 1,3-phenylene radical, the 1,4-phenylene radical and the1,3,5-phenyline radical, R and R each represented hydrogen or an alkylradical having from 1 to 8 carbon atoms, and n is a number correspondingto the valency of R. It is noted that the term 1,3,5-phenyline refers tothe trivalent aromatic ring group C H E which may alternately bedesignated 1,3,5-phenenyl. The aliphatic radicals are divalent and maycontain straight or branched chains and atoms other than carbon atoms,e.g., oxygen and sulfur atoms and the like.

The poly-1,2-alkylenamides included within the scope of the aboveformula are characterized by properties which permit storage withoutspontaneous polymerization. They are controllably reactive to formuseful homopolymers, and are especially useful for the purpose of curingcarboxyl group-containing prepolymers as disclosed herein.

Among the poly-1,2-alkylenamides useful in accordance with the inventionare N,N'-bis-1,2-ethylenadipamide; N,-N'-bis-1,2-propylenadipamide;N,N'-bis-1,2-bu-tylenadipamide; N,N'-bis-1,Z-ethylenisosebacamide;N,N'-bis-1,2-propylenisosebacamide; N,N' -'bis-l,2-butylenisosebacamide;N,N'-bis-1,2-ethylensebacamide; N,N'-bis-1,2-pentylensebacamide;N,N'-bis-1,2-ethylendodecanoyldicarboxylic acid amide; N,N bis 1,2propylentetradecanoyldicarboxylic acid amide;N,N-bis-l,Z-ethylenhexadecanoyldicarboxylic acid amide;N,N-bis-1,2-ethylenoctadeconoyldicarboxylic acid amide;N,N-bis-e'thylenthiodipropionamide; N,N'-bis-ethylenoxydipropionamide;

and the poly-1,2-alkylenamide product of the interreaction ofethyleneimine with Emery 3020-S polymerized fatty acid chloride(prepared by reaction of P01 with Emery 3020-S polymerized fatty acid, aproduct of the polymerization of C unsaturated fatty acid which has aniodine value of 35-45, a neutralization equivalent of 295-310, arefractive index at 25 C. of 1.4858, and a monomerzdimerztrimer weightratio of 3:72:25). Other poly-1,2-alkylenamides useful in accordancewith the invention are 6 N,N'-bis-1,2-ethylenisophthalamide;N,N-bis-1,2-butylenisophthalamide; N,N'-bis-1,2-propylenisophthalamide;N,N'-bis-1,2-octylenisophthalamide;N,N-bis-2,2-dimethylethylenisophthalamide;N,N'-bis-1,2propylenterephthalamide;N,N'-bis-1,2-butylenterephthalamide;N,N,N"-tris-1,2-ethylenetrimesamide;N,N',N"-tris-1,2-propy1entrimesamide;N,N',N"-tris-2-isopropylethylenetrimesamide;

and N,N',N"tris-2,Z-dipropylethylenetrimesamide, etc.

Mixture of these monomers may be produced by employing mixed1,2-alkylenimines in producing them.

The poly-1,2-alkylenamide comonomers are prepared in monomeric form bythe following process: a 1,2- a-lkylenimine having the followingstructure:

OR Rz wherein R and R are as previously defined (such as ethylenimine,1,1-dimethyl-ethylenimine, 1,2-propylenimine, 1,2-butylenimine,1,2-pentylenimine, etc.) is reacted with a suitable polycarboxylic acidchloride to produce the desired substantially pure monomer, withhydrogen chloride as a by-product. The 1,2-alkylenimine is employed in aratio of about 1 mole for each mole of acid chloride group in thepolycarboxylic acid chloride, i.e. in the case of a dicarboxylic acidchloride the molar ratio of the reactants would be two mols of the1,2-alkylenimine to one mole of the dicarboxylic acid chloridecoreactant. Advantageously, an excess of 1,2-alkylenimine, such as about5 per-cent by weight, over and above this ratio may be employed,although an excess of up to about 25 percent may be employed.

Desirably, the 1,2-alkylenimine is introduced in an aqueous solutionwhich also contains an ammonium or alkali metal carbonate, such assodium, potassium, or

lithium carbonate, which acts as an acid-acceptor to neutralize thehydrogen chloride formed during the reaction of the process. When ahigher 1,2-alkylenimine than 1,2-ethylenimine, i.e., one containing morethan 2 carbon atoms, is employed, an ammonium or alkali-metalbicarbonate, such as sodium, potassium, or lithium bicarbonate may beused as the acid-acceptor instead of a carbonate. This aqueous solutionis intimately mixed with the polycarboxylic acid chloride dissolved in asubstantially water-immiscible organic solvent which is chemically inertto both the reactants and the reaction products and in which theresulting poly-1,2-alkylenamide is soluble. The poly-1,2-alkylenamidemonomer reaction product is then recovered in a relatively pure, stablestate in high yield from the organic solvent, in which it collects asthe reaction proceeds, by evaporating the solvent. By this process ofproducing the monomers any possibility of attack on and decomposition ofthe poly-1,2-alkylenamide by hydrogen chloride formed during the courseof the reaction is effectively minimized.

The preparation and properties of the poly-1,2-alkylenamides useful inthe preparation of the copolymers of the invention are disclosed in theapplication of George H. Smith, S.N. 832,152, filed August 7, 1959 nowU.S. Patent 3,115,474 and SN. 840,255, filed September 16, 1959, nowU.S. Patent 3,115,482 wherein the preparation and properties of a numberof these substances are disclosed in detail. 111 SN. 840,255, forexample, the preparation of the N,N'-bis-l,2-alkylenisosebacamides fromthe corresponding alkylenamides and the diacid chloride of isosebacicacid (a product consisting of 72-80 percent of Z-ethylsuberic acid, 1218percent of 2,4- diethyladipic acid and 610 percent of n-sebacic acid) isdescribed.

The poly-1,2-a1kylenamide monomers are preferably utilized insubstantially pure form, i.e., having at least 85 percentof the amidegroups thereof in the form of azirane rings. This may be expressed alsoas a composition containing at least 85 percent of the nitrogen(excluding nitrogen not originally derived from the alkylenimine) in theform of azirane rings. Lots which contain less than 85 percent of thetheoretical amount of the azirane ring according to the structure of theparticular polyalkylenamide correspondingly contain more than about oneweight percent halide (calculated as the halogen). Such impure productsare unstable to aging and cannot be heated without degradation, whiletheir reactions with other reactants may not be controllable.

The polymer-producing composition provided by admixture of thepolymerized higher fatty acids and the poly-1,2-alkylenamides includedwithin the scope of the invention are generally speaking, when firstprepared, substantially liquid or viscous, semi-solid substances whichcan be compounded with fillers and the like to produce more or lessviscous products. (By the term substantially liquid as used throughoutthe specific-ation it is meant that the substance is capable of flowing.Materials of very high viscosity may required warming to facilitatehandling.) The uncured systems may be poured or otherwise introducedinto molds surrounding circuits, wires, etc. which are to beencapsulated. The compositions undergo spontaneous curing producingcured polymer systems which provide firmly-adhered, solidchemically-inert, moisture and solvent resistant encapsulations havinguseful electrical properties. Mold release agents are commonly utilizedto prevent adhesion when the compositions are used as molds.

For many applications, compositions consisting solely of polymerizedpolyene higher fatty acid and poly-1,2- alkylenamide will be preferred,e.g., in electrical encapsulations, since the resulting electricalproperties are often best when no adjuvants are included. In other casesit may be found desirable to load or extend the resinous composition,e.g. by the addition of particulate or fibrous fillers such as fullersearth, quartz flour, asbestos, glass filaments, etc. or to otherwisemodify the electrical, physical or chemical properties of the resin byincorporation of plasticizers, colorants, resins, conductive materialsuch as carbon or metal powders, etc. which may be considered ,asadjuvants and the like. The finer fillers are good reinforcing agentsfor these systems, neutral fillers such as calcium carbonate, iron oxideand titanium dioxide being preferred. Acidic fillers such as certaincarbon blacks and silicas can also be used if proper adjustments aremade for pH (e.g. addition of increased amounts ofpoly-1,2-a1kylenamide).

Among the other adjuvants which may be used with the compositions of theinvention are solvents, e.g. hydrocarbons such as heptane, benzene,toluene and xylylene, chlorinated solvents such as carbon tetrachloride,chloroform and trichloroethylene, ketones such as acetone and methylethyl ketone, and alcohols such as isopropanol; and antioxidants, e.g.symmetrical di-beta-naphthyl paraphenylene diamine (available under thetrade designation Agerite White), certain liquid phenol-formaldehyde A-stage resins (e.g. Stabilite White liquid antioxidant), diorthotolylethylene diamine (available under the trade designation Stabilite Alba),etc.

Broadly, the curable compositions of the invention are prepared bysimple admixture of the components thereof. While an amount of thepoly-1,2-alkylenamide, the imine ring content of which is equivalentstoichiometrically to the number of carboxyl groups present in theselected polymerized polyene higher fatty acid component, may beemployed, and some curing effect can be obtained with even smalleramounts, more complete cures are effected when amounts greater thanstoichiometric amounts are employed, ranging upwards from 10 to 100percent greater; and it is ordinarily preferred that about 20 .to 40percent excesses of the theoretical stoichiometric equivalent of thepoly-1,2-alkylenamide be used in order to compensate for any inerts inthe poly-1,2-alkylenamide, its adsorption on and reactivity withfillers, etc. The initiation of and the rate of cure are dependent to adegree upon the temperature, the viscosity of the mixture and the amountof the particular poly-1,2-alkylenamide which is employed. Bymaintaining the mixture at low temperatures, for example, about 010 C.,the polymerization is retarded and increased pot life is obtained.

In order more clearly to disclose the nature of the present invention,several examples illustrating products and compositions thereof will nowbe described. It should be understood, however, that this is done solelyby way of example of the best mode presently contemplated for carryingout the invention, and is intended neither to delineate the scope of theinvention nor to limit the ambit of the appended claims. All parts areby weight unless otherwise designated. At least percent of the amidegroups of the poly-1,2-alkylenamides used in the examples are in theform of azirane rings.

Example I About parts of Emery 3055-S polymerized fatty acid (having adimer-trimer ratio of about 15:85) and 53 parts of liquidN,N-bis-1,2-ethylenisosebacamide are mixed thoroughly. A portion of theresulting viscous syrup is placed in a mold and heated in an air oven at85 C. for about 2 hours, whereupon a rubber-like solid having ahardness, Shore A2 (ASTM D676-49T), of 44 is formed. After a post-cureof 14 hours at C., the hardness (Shore A-2) is 49. The amount of waterabsorption, as determined by immersing /8" thick discs of the resin in25 C. water for 24 hours, is 1.07 percent.

The resistance to deformation under load at elevated temperatures ofthis bis-amide-higher fatty acid copolymer is very great, thusemphasizing its excellent high-temperature properties. This property ismeasured as the temperature at which a weighted bar will deform curedresin specimens which have rectangular cross-sections of 0.5 inch by0.625 inch and which are 5 inches in length. The specimen to be testedis placed in a temperature controlled test chamber on parallel metalsupports which are 4 inches apart and oriented so that the 0.5 inchdimension is vertical. A bar bearing a 3 pound load is placed againstthe specimen midway between the supports and parallel to them, the barand the supports all being rectangular in cross-section but roundedalong their respective contacting edges to a /3" radius cross-section.The temperature in the test chamber is then raised at a rate of about 5C./ minute while the specimen is observed. In the present case noappreciable additional distortion of the bis-amide copolymer sample isnoted as the temperature of the test chamber is raised fromapproximately 25 C. up to C., at which point the test is terminated.

The viscous syrupy mixture of 100 parts of Emery 3055-8 polymerizedfatty acid and 53 partsof N,N'-bis- 1,2-ethylenisosebacamide can bereduced in viscosity as desired by adding solvents to it. Such a mixtureformed by adding 25 parts of xylylene to the above constituents isapplied to wooden test panels, the solvent is allowed to evaporate atroom temperature and the panels are placed in an oven at 120 C. for 2hours. At the end of this cure cycle, a tough, adherentprotectivecopolymeric coating has formed on the panels. Usefulprotective coatings can also be formed on other common materials ofcoristruction, such as metals, ceramics, etc.

In another preparation, a solid, tack-free, rubber-like product isobtained in about 15 minutes after mixing together at room temperatureabout 100 parts of Emery 3055-8 polymerized fatty acid with 41.6 partsof liquid N,N'-bis-1,Z-ethylenisosebacamide. A second portion of uncuredsyrupy polymer mixture of the same composition is poured into open moldsand cured for 14 hours at 120 C. The resulting rubber is subjected to aseries of 9 electrical and physical tests the results of which are asfollows:

Bis-amide-cured Electrical properties fatty acid polymer Dielectricconstant (ASTM D150- 54T), 1 kc., C 4.5 Dissipation factor (ASTM C150-54T), 1 kc., 25 C 0.064 Physical properties I Scott brittleness, T C.)(ASTM 10 D764-57T) to Gehman T C.) (ASTM D1053- 54T) +11 Tensilestrength, p.s.i. 800 Elongation, percent 90 15 Set at break, percent 1 0Volume swelling, percent (ASTM D471-T):

:30 isooctaneztoluene, 48 hrs. at

82 C. 40 20 Water, 70 hrs. at 82 C 0 1 Tensile strength, elongation andset at break are measured using dumbbell-shaped specimens 0.125 wide,0.080 thick and 0.5 between bench marks at a jaw separation rate of 2inches per minute. Test values correlate with those from 10 the liquidmixture into a tack-free rubber which has the following physicalcharacteristics:

Mechanical properties- Immediately after curing:

Tensile strength, p.s.i 255 Elongation, percent 160 Set at break,percent 0 After air aging 9-6 hr. at 177 C.:

Tensile strength, p.s.i. 690

Elongation, percent 0 Weight loss, percent 20 Low temperatureflexibility:

Gehman T C.) 6

Scott brittleness, T c. -7

' Volume swelling, percent:

70:30 isooctaneztoluene, 48 hrs. at 82 C. 15

Water, 70 hrs. at 82 C. 5 Water absorption (at 22 C.):

24 hours, percent 0. 63

7 days, percent 1.19

1-0 days, percent 1.31 Specific gravity, gm./rnl. 1.02

Example 2 The following series of polymerized mixtures are prepared,with warming where solid poly-1,2-alkylenamides are used, for thepurpose of comparing them as to their mechanical properties, lowtemperature flexibility, electrical and solvent resistance properties:

Lot Constituents (indicated in parts by weight under lot designations) AB C D E F G N,N -bis-1,2-ethylenisosebacamidc N,N-bis-1,2-ethylenisophthalamidm N,N'-bis-l,Q-propylenisosebacamideEmery 3079-8 polymerized fatty acid (Dimer-trimer acid ratio :5) 25Emery 3055-8 polymerized acid (Dimcr-trimcr acid ratio 15:85) 100 100100 100 100 75 Ratio-Imine RiugzCOOH 8/4 1/1 4/3 3/2 5/4 5/4 5/4resulting resin is sufiiciently fluid at room temperature to be pouredinto casting molds. The castings cure bub- These mixtures are pouredinto open molds, cured for 14 hours at C. and subjected to the followingtests:

Lot

A B O D E F G Mechanical tests:

Tensile Strength, p.s.i 85 240 800 300 3, 380 605 1, 350

Elongation, percent- 135 90 95 O Set at Break, percent- 0 0 0 0 0 0 0After Air Aging 96 hrs. at 177 C.

Tensile Strength, p.s.i 275 480 580 340 641 335 Elongation, percent. 0 00 O 0 0 Weight Loss, percent 2. 6 2. 6 3. 0 3.0 1. 7 7 3. 0 LowTemperature Flexibility Tests:

Gehman T n, C 6 11 10 15 16 Scott Brittleness, TB, C 27 to 29 54 to -5835 to 40 32 to -35 0 66 to 70 30 to -35 Volume Swelling percent:

70:30 Isooctaneztoluene, 48 hrs. at 82 0..-- 59 59 40 40 41 49 45 Water,70 hrs., 82 C- 7 0 7 7 0 15 Electrical Tests:

Dissipation factor 1 kc., 25 C 0. 263 (1. 2 0. 0635 0.0919 0.0012 0.0720. 0364 Dielectric constant 1 kc., 25 C 6.11 5.60 4. 50 6. 00 3. 86 3.77 4. 93

1 Too rigid for test.

ble-free in 24 hours at room temperature to a soft rubberlike solid,anda 1; z hour cure cycle at 120 C. converts With regard to theforegoing electrical test data, it should be noted that the product ofthe dielectric conelectric (e.g-. stresses and strains in the cureddielectric 10 and imparted to the component, convenience of handling thedielectric duringencapsulation, adhesion to the com-,

ponent, resistance of the cured dielectric to its environment, etc.) maybe more critical.

The following series of copolymers is prepared to compare certain oftheir electrical properties, the number of parts of each component beingstated.

N ,N -bis-1,2-propylenissebaeamide N ,N bis-1 ,2-ethylenisosebacamide N,N -bis-1 ,Z-ethylenseb acamide N ,N -bis-l ,2-ethylenisophthalamidEmery 3055-8 polymerized fatty a "Emery 3079-S polymerized fatty aciThese mixtures are cast into 0.0080 inch thick films and cured for 1hour at 120 C. The volume resistivity and dielectric strength of theresulting resins are then evaluated as follows:

12 7 Example 3- The following two compositions are prepared by warmingthe constituents (indicated in parts by. weight) slightly, and thenmixing them:

Lots

N,N-bisl,Z-ethylenisophthalarnide n 10. 8 10. 8 Emery 3055-8 lolymerizedfatty acid 30 18.

The resulting smooth mixtures are poured into open molds. Lot A forms atough rubber after a cure of 1 hour at 93 C. Lot B forms a soft,non-tacky semi-rigid solid after Lot Numbers standing for 24 hours atroom temperature and a tough but flexible resin after a cure of 1 hourat 93 C.

Example 4 About 100 parts of Emery 3055-S polymerized fatty volumeResistivity acid are mixed with 22.5 parts of N,N-bis-1,2-ethyleniso-Lot No (s l lltl l l gfig g g) A Difiectgic str gngth I sebacamide and22.5 parts of N,N'-bis-l,2-ethyleniso- C ST 3 5 35 phthalamide withwarming. The resulting low viscosity liquid mixture is readily pouredinto an open mold and 1 X, 492 reacts rapidly in a A" thick casting withthe evolution of W heat to yield a transparent brownish rubber-likesolid 2 19x10, 396 which is free of air bubbles. After this casting isallowed a to stand overnight at room temperature, its hardness v3 1 5X10533 (Shore A-Z) is found to be 31. This value is increased to 7 8 43 ifthe sample is heated for one hour in an air oven at 4 10 348 150 C. Noshrinkage takes place during the cure.

4X10 Example 5 5 W 303 5 About 100 parts of the liquid tetrameric acidproduct 6 x10, 249 4308-1 polymerized fatty acid are mixed thoroughly17555? with various amounts of poly-1,2-alkylenamides (with 7 11x10 715warming where required) as shown in the following table. W A portion ofthe resulting viscous syrup from each lot is 2 2X1012 spin-cast undervacuum in an oven at 120 C. for 1 hour. 8 610 3x10 The physicalcharacteristics of the films thus formed are also given in the table.

Lot No.

Constituents (parts by weight):

4308-F polymerized fatty acid 100 100 100 100 100N,N-bis-1,2ethylenisosebaeamide. 5O N,N bis-1,Z-ethylensebacamide 5ON,N-bis-1,2-ethylenisopbthahmidp 43 N,N-bis-1,2-propylenisophthalamide.N,N-bis-1,2-propylenisosebacamide Tensile Properties Immediately aftercuring:

Tensile Strength, p.s.i 140 410 570 140 Elongation, percent 35 20 55 1Set at Break, percent 0 0 0 0 0 After Air Aging 96 hrs. at 177 C.:

Tensile Strength, p.s.i 455 645 3, 000 3, 700 550 Elongation, percent"40 10 10 1O 25 Weight Loss, percent 15.3 18 15.1 15.8 19. 7LowGTgmperalture llexibility:

e man 10, 10 +12 +15.5 6.5 Scott Brittleness, TB, C -59 to 63 -35 to 40-22 to -26 -22 to -26 -41 to -43 Volume Swelling, percent:-

70; 3O Isooctaneztoluene (48 hrs. at 82 C) 31.3 31. 3 31.3 39.9 39.9Water (70 hrs. at 82 c.) 7. 4 15.1 15 1 15.1 15.1 Watgri fibsorption at22 0.: 1

rs., percent 2. 4 3.47 1.31 1.01 1.58 7 'days, percent. 5.12 7. 3 3.062. 47 3. 64 11 days, percent 6. 2 8.57 3. 54 2. 98 4. 28

About 100 parts of 1 3 Example 6 StableN,N'-bis-1,2-propylenterephthalamide monomer useful for reacting withthe polyene higher fatty acids is prepared as follows: about 400 ml. ofwater, 41.4 grams (0.3 M) of potassium carbonate and 23.9 grams (0.42 M)of 1,2-propylenimine are added with stirring and cooling to aj1000 ml.three-necked flask equipped with a stirrer, thermometer, condenser anddropping funnel. When solution occurs and at a temperature ofapproximately 12 C., a solution of 40.6 grams of terephthaloyldichloride in 300 ml. of benzene is added dropwise with vigorousstirring over a period of approximately 45 minutes. The temperature ismaintained at approximately 12-15" C. by means of an ice bath. After thebenzene solution is added, the ice bath is removed and stirring iscontinued for an additional hour. The benzene layer is then separatedfrom the aqueous layer and the solvent is removed by distillation undervacuum. A yield of 47.8 grams (98 percent of theoretical) of whitecrystalline N,N'-bis-1,2- propylenterephthalamide monomer is obtained.The material, which melts at about 96-108 C., is found to con tain 11.30percent of nitrogen and 46.0 percent of 2-methylazirane radical ascompared to calculated values of 11.48 percent and 45.9 percentrespectively.

Other alkylenterephthalamides are prepared in similar manner, usingethylenimine or appropriately substituted ethylenimines as startingmaterials. Thus, using ethylenimine and 1,2-butylenimine, for example,in corresponding stoichiometric amounts, there are obtained,respectively, N,N-bis-ethyleneterephthalamide, M.P. ca. 140 C., andN,N'-bis-1,2-butylenterephthalamide, M.P. 98-110" C.

About 100 parts of Emery 3055-8 polymerized fatty acid are mixed with 41parts of N,N-bis-1,2-propylenterephthalamide and the mixture is heatedwith agitation until a homogeneous mixture is obtained. The solution isthen cured for 30 minutes at 120 C. to form a flexible, solid resinsimilar to those of the previous examples.

Example 7 Emery 3055-8 polymerized fatty acid are mixed with 45 parts ofN,N'-bis-1,2-butylenterephthalamide and the mixture is heated withagitation until a homogeneous mixture is obtained. The solution is thencured for 30 minutes at 120 C. to form a flexible, solid resin similarin properties to those of the previous examples.

Example 8 About 100 parts of Emery 3055-8 polymerized fatty acid and 52parts of liquid N,N-bis-1,2-ethylenisosebacamide are mixed thoroughly.This liquid mixture is poured into a 600 ml. stainless steel beaker inwhich is is added to the beaker to submerge the pattern to a point about1%" above the threads. 'The liquid becomes tackfree in about 20 minutesat approximately 25 C. and after 24 hours at 25 C. it has cured to atough rubber. The rubbery mold containing the pattern is removed fromthe beaker and the mold is slit along one side to remove the pattern. Anexcellent negative reproduction of the pattern including the threads isachieved in the rubbery mold, due particularly to the facts that themold before curing had been a mobile liquid, that no bubbles aregenerated either within the copolymer itself or at its surfaces duringthe curing process, that the uncured liquid is 1,00 percentsolids-forming and therefore undergoes no appreciable amount ofshrinking during curing and finally that, being rubbery in nature, itcan be removed from complex (e.g. undercut) shapes easily and withoutdamage. A particular advantage of this composition in flexible moldapplications (as compared to other flexible mold compositions) is itsexcellent ability to withstand temperatures up to at least 350 C.without appreciable damage and to be reused after heating. This abilityto withstand high temperatures can of course be extended even furtherwith the use of fillers, antioxidants and other compounding techniquesknown to the art. Thus, in addition to being useful in the casting ofmaterials in which high temperature resistance of the mold isunnecessary, such as various resins and plaster of Paris, it may also beused in the casting of low melting metals and metal alloys such as forexample Woods metal, lead solder, tin, lead, etc. Specimens of thiselastomer are also subjected to a series of standard tests, the resultsof which are as follows:

Mechanical properties:

Tensile strength, p.s.i 480 Elongation, percent 125 Set at break,percent 0 Low temperature flexibility tests:

Scott brittleness, T C. below) Volume swelling:

70:30 isooctaneztoluene, 48 hours at 82 C. 39.9

Example 9 A series of four liquid mixtures of poly-1,2-alkylenamides andpolymerized polyene higher fatty acids are prepared according to thefollowing compositions (indicated in parts by weight under each lot):

suspended a cylindrical pattern about 2" in diameter and threaded at oneend, previously coated with a mold release agent.

A suflicient amount of the liquid mixture The respective gel times ofthe lots at room temperature and the appearances of the resulting solidpolymers are are follows:

Lots

A B C D Gel Time at Approximately 30 5 10 10.

25 0. (minutes). Color Light Black Light Light yellow yellow yellow.

The respective liquid mixtures are poured into open aluminum molds andcured for 24 hours at approximately C. and 1 hour at 120 C. Thefollowing data are obtained from tests run on these rubbers:

16 and alkyl radicals containing from 1 to 8 carbon atoms; and n is anumber corresponding to the valency of R. 5. A polymer comprising apolymerized polyene higher fatty acid, said acid containing from about14 to 22 car- A B o D Mechanical Properties:

Tensile Strength, p.s.i 158 166 163 287 Elongation at break, percent N120 50 130 155 Low Temperature Flexibility Tests: Scott Brittleness, Tn,C 36 8 56 38 Gehman Tests, 0.:

T2 1 -1 T5" -4 7 Tio- 8 -11 T100 18 18 After Air Aging 96 hrs. at 177 C.

Tensile Strength, p.s.i 100 294 207 92 Elongation at Break, percent 3822 42 48 Volume Swelling:

70:30 Isooctaneztoluene, 48 hrs. at 82 O 7. 3 9. 2 7. 3 7. 0 Water, 70hrs. 82 C 48.1 27.0 54.0 69.0

Example 10 bon atoms, reacted with an N,N,N-tric-1,2-a1kyleneamiderepresented by the formula: About 36 parts of N,N,I"-tris-1,2-propylentrimes- R amide are dissolved in 150 parts ofchloroform and the 1 resulting solution is mixed into 100 parts of EmeryCH2C 3162-8 polymerized fatty acid. The mixture is stirred and warmedslightly until it is homogeneous and is al- 00 lowed to stand for 48hours at room temperature. The resulting tack-free, flexible material,which is transparent H H and brown in color, is then post-cured for onehour at K 2 100 C. to form a tough, leathery resin. R1 N o 0- --OON R1The terms and expressions which are employed herein are used as terms ofdescription and not of limitation, and it is not intended, in the use ofsuch terms and ex- Z pression-s, to exclude any equivalents of thefeatures shown wherein R and R each represent a member of the group anddescribed or portions thereof, but it is recognized that consisting ofhydrogen and alkyl radicals containing from various modifications arepossible within the scope of the 1 to 8 carbon atoms. invention claimed.6. A polymer comprising a polymerized polyene higher What is claimed is:fatty acid, said acid containing from about 14 to 22 car- 1. Al00percent solids-forming liquid comprising a bon atoms, reacted with anN,N-bis-l,2-alkylene amide mixture of a polymerized polyene higher fattyacid, said represented by the formula: acid contatining from about 14 to22 carbon atoms, and

CH2 CH2 a poly-1,2-alkylenam1de.

2. A polymer comprising a polymerized polyene higher" 1 0 R1 fatty acid,said acid containing from about 14 to 22 carbon atoms, reacted with apoly-1,2-alkylenamide.

. 2 2 3. A polymer comprising a polymenzed polyene higher I fatty acid,said acid-containing from about 14 to 22 car- Whereln R is a divalentaliphatic radical having about-4 bon atoms, reacted with apolyamide-containing com-pot 53 carbons, and R and R each represent amember sition selected from the group consisting of aliphatic 55 of thegroup consisting of hydrogen and alkyl radicals N,N'bis-1,2-alkylenamides, aromatic N,N-bis-1,2-alkycontaining from 1 to 8carbon atoms. lenamides and aromatic N;N,N"-tris-1,2-alkylenamides. '7.A polymer comprising a polymerized polyene high- 4. A polymer comprising:a polymerized polyene higher er fatty acid of the group consisting ofdimeric higher fatty acid, said acid conttaining from about 14 to 22fatty acids and trimeric higher fatty acids, which acids carbon atoms,reacted with a poly-1,2-alkylenamide repcontain from about 14 to 22carbon atoms, reacted with resented by the f r ula; apoly-1,2-alkylenamide represented by the formula:

0 CH2 t N R 0 CH2 1 u RC R1 n wherein R represents a member of the groupconsisting of divalent aliphatic radicals having from about 4 to 53carbon atoms, the 1,3-phenylene radical, the 1,4-phenylwhereinRrepresents a member of the group consisting of ene radical and the1,3,5-phenyline radical; R and R divalent aliphatic radicals having fromabout 4' to 53 careach represent a member of the group consisting ofhybon atoms, the 1,3 phenylene radical, the 1,4-phenylen ,drogen andalkyl radicals containing from 1 to 8 carbon radical and the1,3,5-phenyline radical, R and R each atoms; and n is a numbercorrresponding to the valenc represent a member of the group consistingof hydrogen 7.5 of R,

1 7 8. A polymer comprising a dimeric polyene higher fatty acid, saidacid containing from about 14 to 22 carbon atoms, reacted with apoly-1,2-alkylenamide represented by the formula:

wherein R represents a member of the group consisting of divalentaliphatic radicals having from about 4 to 53 carbon atoms, the1,3aphenylene radical, the 1,4*phenylene radical and the 1,3,5-phenylineradical; R and R each represent a member of the group consisting ofhydrogen and alkyl radicals containing from 1 to 8 carbon atoms; and nis a number corresponding to the valency of R.

9. A polymer comprising a trimeric polyene higher fatty acid, said acidcontaining from about 14 to 22 carbon atoms, reacted with apoly-1,2-alkylenamide represented by the formula:

I? /CH2 RC-N I R] l Rz n wherein R represents the divalent hydrocarbonresidue of isosebacic acid which consists essentially of from about72-80% of CH CH(C H )-(CH 12 to 18% of CH(C H )-CH CH(C H )CH and 610%of normal (CH 11. A polymer comprising a polymerized polyene higherfatty acid, said acid containing from about 14 to 22 carbon atoms,reacted with fN,N'-bis-1,2-propylenisosebacamide represented by theformula:

CH2 (W C OHz (3H3 OH: wherein R represents the divalent hydrocarbonresidue derived from isose'bacic acid which consists essentially of fromabout 72-80% of ---CH CH(C H )(CH 12l8% of CH (C H )-CH -CH (C H )CH and6-10% of normal (CH 12. A polymer comprising a mixture of dimeric andtrimeric acids derived from linoleic acid, reacted withN,N-bis-1,2-ethylenisosebacamide represented by the formula:

wherein R represents the divalent hydrocarbon residue derived fromisosebacic acid which consists essentially of from about 7280% of 13. Apolymer comprising a mixture of dimeric and trimeric acids derived fromlinoleic acid, reacted with N,N'-bis 1,2-ethylensebacamide representedby the form-ula:

14. A polymer comprising a mixture of dimeric and trimeric acids derivedfrom linoleic acid, reacted with N,-N-bis-l,2-ethylenisophthalamiderepresented by the formula:

15. A polymer comprising a mixture of dimeric and trimeric acids derivedfrom linoleic acid, reacted with a poly-1,2-alkylenamide represented bythe formula:

wherein R represents a member of the group consisting of divalentaliphatic radicals having from about 4 to 53 carbon atoms, the1,3-phenylene radical, the 1,4-phenylene radical and the 1,3,5-pheny1ineradical; R and R each represent a member of the group consisting ofhydrogen and alkyl radicals containing from 1 to 8 carbon atoms; and nis a number corresponding to the valency of R.

16. A polymer comprising a polymerized polyene higher fatty acid, saidacid containing from about 14 to 22 carbon atoms, reacted with aplurality of curing agents chosen from the group consisting ofpolyalkylenamides represented by the formula:

wherein R represents a member of the group consisting of aflkyleneradicals having from about 4 to 53 carbon 18. A polymer comprising apolymerized polyene higher fatty acid, said acid containing from about14 to 22 carbon atoms, reacted with N,N-bis-1,Z-butylenterephthalamiderepresented by the formula:

19. A polymer comprising a polymeric polyene higher fatty acid, saidacid containing from about 14 to 22 carbon atoms, cured with anN,N'-bis-1,2-alkylene amide represented by the formula:

where R represents a member of the group consisting of alkylene radicalshaving from 6 to 18 carbon atoms and the 1,3-phenylene radical, and Rand R each represent a member of the group consisting of hydrogen andalkyl radicals containing from 1 to 8 carbon atoms.

20. A polymer comprising a polymeric polyene higher fatty acid of thegroup consisting of dimeric higher fatty acids and trimeric higher fattyacids, which acids contain from about 14 to 22 carbon atoms, cured withan N,N-bis- 1,2-a'lkyleneamide represented by the formula:

where R represents a member of the group consisting of alkylene radicalshaving from 6 to 18 carbon atoms and the 1,3-phenylene radical, and Rand R each represent a member of the group consisting of hydrogen andalkyl radicals containing from 1 to 8 carbon atoms.

21. A polymer comprising a dimer of a higher fatty acid which acidcontains from about 14 to 22 carbon atoms, reacted with anN,N-bis-1,Z-aIkyleneamide represented by the formula:

where R represents a member of the group consisting of alkylene radicalshaving from 6 to 18 carbon atoms and the 1,3-phenylene radical, and Rand R each represent a member of the group consisting of hydrogen andalkyl radicals containing from about 1 to 8 carbon atoms.

22. A polymencomprising trimer of a higher fatty acid which acidcontains from about 14 to 22 carbon atoms cured with anN,N'-bis-1,2-alkyleneamide represented by the formula:

where R represents a member of the group consisting of alkylene radicalshaving from 6 to 18 carbon atoms and the 1,3-phenylene radical, and Rand R each represent a member of the group consisting of hydrogen andalkyl radicals containing from about 1 to 8 carbon atoms.

23. A polymer comprising a mixture of dimeric andv trimeric acidsderived from linoleic acid, cured with an N,N'-=bis-l,2-alkyleneamiderepresented by the formula:

where R represents a member of the group consisting of alkylene radicalshaving from 6 to 18 carbon atoms and the 1,3 phenylene radical, and Rand R each represent a member of the group consisting of hydrogen andalkyl radicals containing from 1 to 8 carbon atoms.

25. A polymer comprising a polymeric polyene higher fatty acid, saidacid containing from about 14 to 22 carbon atoms cured with a pluralityof curing agents chosen from the group consisting ofN,*N-bis-l,2-alkylene amides represented by the formula:

where R represents a member of the group consisting of alkylene radicalshaving from 6 to 18 carbon atoms and the 1,3-phenylene radical, and Rand R each represent a member of the group consisting of hydrogen andalkyl radicals containing from 1 to 8 carbon atoms.

No references cited.

CHARLES B. PARKER, Primary Examiner.

A. H. SUTTO, Assistant Examiner.

1. A 100 PERCENT SOLIDS-FORMING LIQUID CONPRISING A MIXTURE OF APOLYMERIZED POLYENE HIGHER FATTY ACID, SAID ACID CONTAINING FROM ABOUT14 TO 22 CARBON ATOMS, AND A POLY-1,2-ALKYLENAMIDE.